It might be ziricote. Take a look through some of these pictures and I bet you’ll see some similarities. If not, it could be macassar ebony. Both are tan in color with jet black grain lines with a tendency to be highly irregular.

I don’t think it’s cocobolo based on the color since it is usually somewhere between orange and dark brown in color, although it does have irregular black grain lines..

-- Jay Gargiulo, Naples, FL www.swallowtailwoodcraft.com "Once you understand the way broadly, you can see it in all things."- Miyamoto Musashi

The cocobolo shown in the book I just got for my birthday looks a bit more burgundy than gray, this could be due to oxidation I suppose. It would be nice to look at the wood and at least narrow it down based on what it could be, instead of trying to memorize the book.